Dishwasher



March 9, 1954 J. M DONALD EIAL DISHWASHER 3 Sheets-Sheet 2 Filed Dec.

awe/rm [35135 55 RMEHJJUWERHFT JUHN MIIED NFlLlIi Patented Mar. 9, 1954 UNITED STATES OFFICE DISHWASHER Michigan Application December 29, 1945, Serial No. 638,273

9 Claims.

The present invention relates to improvements in fully automatic dishwashers.

Automatic dishwashers for home use have been an active subject for investigation for many years. Of the multitude proposed only a few have reached the consumer. Those that have been placed in production have been relatively expensive and beyond themeans of the average person. Another factor that has restricted the general acceptance and use of such devices has been their limited cleaning capacity, which has necessitated precleaning of the dishes to a considerable extent before placing the dishes in the device. This precleaning has been necessitated by the inability of the device to remove certain food particles and the tendency of the food particles unless removed to accumulate and clog the drain system. Further, devices on the market at this time do not perform the drying operation as well as desired, especially with respect to glasses and silverware.

According to the present invention, both the washing and drying operations in an automatic dishwasher have been substantially improved through the provision of a source of extremely hot water available in required quantities throughout the cycle of operation. To improve the selfcleaning or the vat and avoid accumulation of food particles in and about the drain system, the drain for the system is in the form of a sump concentric with and surrounding the impeller shaft with a valve likewise concentric with and surrounding the impeller shaft, controlling the drainage from the vat into the sump. Other improvements in venting, regulation of washing and rinsing water, and control of the cycle of operations has contributed to the improved performance, ease of operation, and cost of construction.

Thus one of the objects of the present invention is to provide an improved dishwasher, fully automatic in operation.

Another object is to provide novel means for heating, supplying and metering water in automatic dishwashers.

Another object is to provide an automatic dishwasher having improved arrangements for venting the steam to assure the complete drying of the dishes and silverware at the end of the washing and rinsing cycle.

Another object resides in the improvements for the control. of the lid of the vat.

Another object is to provide a fully automatic and novel structure for operating the drain valve of an automatic dishwasher.

A still further object of the invention is to provide an automatic dishwasher'in which the drain 2 valve is opened and closed with the starting and stopping of the impeller motor.

A still further object of the invention is to provide a fully automatic dishwasher which is of eflicient operation, designed to be inexpensively manufactured, and capable of being used for long periods without appreciable maintenance.

These and other objects and advantages residing in the combination, construction and arrangement of parts, the cycle of operation and other details associated with the controls and associated automatic features of the device will become apparent from a consideration of the following specification and appended claims.

In the drawings,

Fig. 1 is a perspective view of an automatic dishwasher embodying the principles of construction of the present invention, with the outer casing broken away to show the interior structure,

Fig. 1a is a fragmentary detail of the lid or cover hinge,

Fig. 2 is a vertical cross-sectional view through the vat and a portion of the structure associated with the motor and impeller.

Fig. 2a is a detail of the latch release structure the figure being a plan of this structure as seen in Figure 2,

Fig. 3 is a diagrammatic layout of the electrical circuit and associated parts,

Fig. 4 is a bottom View of the timer mechanism partly shown in broken cross section, Fig. 5 is a cross-sectional view taken on line V-V of Fig. 4, and

Figs. 6 and 7 are fragmentary perspective views of certain details of construction of the timer mechanism.

Referring to the illustrated form of the invention, a fully automatic dishwasher is disclosed as comprising a suitable framework l0, supporting the vat i 2, which consists of a cylindrical portion It, and a frustrated conical portion It. The vat i2 and associated structure are enclosed by suitable side panels Ill. The top panel 29 has a back portion 22 and an opening 24 within which the lid hinge or cover 26 operates.

Referring to Fig. 2, the vat H has been illustrated with all supporting structure for dishes and silverware removed for greater clarity of the remaining structure. Enclosing the opening 28 in the conical bottom portion it of the vat I2 is the casting 36 having an annular flange 32 and held in position by screws 34. A suitable gasket, not shown, will be employed to prevent leakage between the joints between the casting 3H and the conical bottom portion l6.

As illustrated, the casting 30 defines a sump 36 as well as a supporting framework 33 for the motor 46. The motor shaft 42 drives the outer sleeve 44 which in turn drives the shaft 46 having the impeller 48 for washing and rinsing water removably connected to its upper end through a screw 50. The position of the impeller 48 on the shaft 46 is determined by a cross pin 52 which engages in a recess 54 and acts also as a driver for the impeller 48.

The centrifugal actuator for the drainage valve and the control of the lid 26 for venting the vat I2 comprises lateral ears 56 to which heavy arms 58 are pivoted to function as flyball governors. At the upper end of the arms 58 are pivotal connections 60 with links 62 having piv otal connections at 64 attached to a sleeve 66 having a free sliding and rotatable fit with respect to the upper end 68 of the sleeve 44 carrying the lateral ears 56 and connected for rotation with the motor shaft 42. A compression spring I holds the centrifugal governor unit in the extended full line position shown in Fig. 2 by engaging with a shoulder I2 of the sleeve 66. As will be readily understood rotational forces will cause the centrifugal governor unit to assume the dotted line position shown in Fig. 2, which will lower the sleeve 66 while the motor 40 is being run.

The valve mechanism for controlling drainage between the vat I2 and the sump 36 preferably takes the form of a poppet valve I3 having an annular flange I4 grooved to receive a soft rubber sealing ring H3 or other equivalent structure. The ring I6 is shown sealing against a conical surface 18 in the casting 30. The structure defining the sump 36 comprises an integral central and vertically extending socket 80 through which the impeller shaft 46 extends freely and with respect to the inner surface of which socket 80 a tube 90 is mounted for vertical reciprocation, this tube resting at its lower end upon a collar 92, itself resting upon the upper end of the sleeve 66, through the medium of a wear washer 94, and the tube 90, at its upper end, having a ring cap 84 secured thereto. This ring cap provides a gland bushing 84a, which has sliding sealing contact with the impeller shaft 46, and an annular end flange 84b, integral with the bushing part 8411 and extending at its outer periphery into an annular recess formed between an inner sleeve 82 and an outer sleeve 82a both of which are connected to be rigid with one another and combine to form the upstanding sleeve part of the drain valve I3. This valve sleeve part has a rigid annular flange 82?) at the upper end, which has a sliding fit with the impeller shaft 46 and by means of which flange 62b the drain valve as a whole is supported upon the top of the reciprocable tube 90 by engagement with the said end flange 64b.

The construction and arrangement is such that when the motor shaft 42 is at rest and the centrifugal governor isaccordingly in the extended condition, as shown in full lines in Figure 2, the collar 62 and hence the tube 90 will be in an elevated position, in which the drain valve is held open as shown in the full lines in Figure 2. When, however, the motor shaft is rotated and the centrifugal governor is moved to the collapsed condition as shown by the dotted lines the collar 92, and hence the tube 90, will be lowered and thereby cause the drain valve also to be lowered and moved into the closed position as shown in dotted lines in Figure 2. The tube 90 is readily slidable for axial movement within the sleeve 86 and as stated is fixed at its lower end to a collar 92 having clearance with the shaft 46 and resting upon the sleeve 66 and spaced therefrom by a wear washer 04.

To hold the collar 92 against rotation, slots 96 are provided upon opposite sides thereof to receive the forked ends 98 of the lever I00. The lever I60 is pivotally supported on the pin I02 carried on the bracket I04 with an extension I06 of the lever I00 carrying an adjustable stop in the form of a bolt I08. Also pivoted on the pin I02 alongside the lever I60, is a lever III) having an extension II2 which is bent laterally to lie in the plane of the lever I00 as shown in Figure 2a. A narrow gap H4 is provided between the lever I66 and the extension H2 into which under certain operating conditions the enlarged head I of a pin I I6 is projected to permit rocking action of the lever I00 to be transferred to the lever IIO. As will be more fully described hereinafter, the pin H6 is under the control of the timer mechanism for the regulating cycle of operation of the dishwasher. A rod II8 is connected at one end to the lever H0 and at the opposite end to the latch I20, which in the position shown in Fig. 2 will project through the opening I 22 to hold the lid 26 closed. A hand opening is indicated at I24 to permit engagement with the spring plunger I26 for projecting the latch I26 out of the opening I22 for opening the lid. The spring I28 continuously stresses the lever H6 in a counterclockwise position to hold the latch I20 in position to engage the catch of the cover 26.

The arrangement for providing at all times an adequate supply of extremely hot water comprises an inlet I30 from a suitable source of cold water under pressure, as for example the conventional municipal water supply. The cola water is directed into a heavily insulated hot water heating tank I32, which is preferably provided with an electric heating element I34 and a standard thermostat I36. A heavily insulated tank of approximately two to three gallons capacity will assure an adequate supply of extremely hot water at all times. As the heavy insulated heater tank I 32 will have very little heat loss, it is not uneconomical to have this storage of hot water at all times although the dishwasher is used only two or three times each day at the most. The tank I32 is under full line pressure at all times with the result that the cold water flows into the tank at the same rate the hot water is drawn from the tank. The electric heating element I34 is of relatively large capacity so that the water stored in the tank I32 may be rapidly heated to the order of F. in a very few minutes so as to provide the necessary hot water within the cycle of operation. The outlet I38 withdraws the water from the tank I32 from the top. The water flows through a solenoid valve I40 past the pressure reducing valve !42 and through the electrically controlled inlet valve I44 to be discharged into the vat I2 through the connection I46. The connection I46 of the vat i2 is preferably in the form of a metering jet which with the pressure regulated by the valve I42 will admit into the vat I2 a certain volume of hot water within a predetermined time interval. Drainage from the vat I2 is through drain connection I48 connecting with the lower level of the sump I36.

The structure for moving and holding the lid 26 in the full line position shown in Fig. 2 is 5 illustrated in Fight. As shown the lid 26-has a hinge bracket I50 which with a bracket I52 and a pin I54 forms a piano hinge of known construction. Also, on the pin I54 is a torsion coiled spring I56 having its ends I58 acting outwardly against the brackets I56 and I52. When the lid 26 is closed as shown in Fig. 1a, the spring I56 is stressed. When the lid 26 is released by the latch I22, the tension in the spring I56 will raise the lid 26 to the venting position shown in Fig. 2.

For controlling the automatic cycle of operation of the dishwasher, a suitable timer mechanism is required. Preferably, the timer is provided vith an electric motor for supplying the energy for driving the timer during the cycle of operation. In the illustrated form the timer comprises a bracket I58 supporting an electric motor I66 for slowly rotating through suitable gearing I62 a cross shaft I64. To permit the shaft I64 to be rotated in a forward direction independently of the motor 566, a conventional ball or pin free wheeling clutch I86 is provided between the gearing I62 and the shaft I64. Thus the shaft I64 may be rotated by the motor I60 in the direction of the arrow of Fig. 6 at a slow speed and it also may be manually rotated or advanced at a more rapid speed in the same direction.

The manual means of operation of the shaft I64 comprises a coupling I58 located between the shaft I64 and the shaft H6 upon which i a sprocket I72 driven by a chain I14 running over a sprocket I76 on a dial shaft I36. A pointer knob I80 is secured to the shaft I78 and sweeps a dial I82 having the station of operation indicated, namely, Oil, On, Wash, Rinse, and KDr3rIS! Rotated by the shaft I64 is cam I84 for operating pin H6. (See Fig, 2a.) A spring I86 holds the pin H6 against .the cam I84 and retracts the pin H6 after it ha been projected by the lobe I86 into the bite between the lever 30 and the extension I I2 to cause the latch I20 to be rocked upon stoppage of the motor 40 to release the lid 26 to a venting position. The outer end I96 of the pin H6 is normally positioned in the plane of the lever I96. A reduced portion'l92 of the pin H6 has clearance in an opening I94 in the bracket I64 for slight lateral movement produced by the movement of the lever I09. When the end I90 is projected into the plane of the extension II2, while still in the plane of the lever I60, it becomes a solid link between these parts and the clockwise movement of the lever I60'is transferred to the lever [I to actuate the latch Referring to th schematic lay out of the electrical circuit shown in Fig. 3 which also illustrates the relationship between the timer structure and the elements controlled thereby, a standard wall plug is indicated at I96 for connecting the dishwasher to any household electrical circuit, with the lead in conductors indicated at I98 and 296. It will be noted that the connecting of the plug #96 into the household circuit will close the circuit in which the electric heater I34 is located through the conductors 262 and 284. The thermostat I36 is shown inserted in the conductor 264 to open and close the heater circuit depending uponthe temperature of the water within the heater I32. It is to be understood from the arrangement illustrated that the hot water heater I32 is connected at all times to assure a supply of extremely hot water for use p whenever it isdesired to operate the-dishwasher.

The-electrical" circuit for the impeller motor 40 includes the conductor 206- connecting with th make and break switch 208 connected with the common conductor 210. In a imilar manner the electrical circuit for the inlet valve I44 comprises the conductor 2I2 connecting with the switch 2I4 which is in turn connected with the common conductor 2I0. The circuit for the operation of the timer motor I comprises a conductor 2I6 connecting the timer motor I 60 in series with the switch 2I8 which in turn is connected on one side with the common conductor 2"). Also in series with the switch 2 I 8 is a signal light 220 having a conductor 222 with a common connection with the conductor 2I6. To facilitate the assembly and replacement of th timer and its associated circuits, a connector plug 224 is provided which enables a plug in connection to be made between the timer and its associated switches and the remaining electrical circuits controlling the inlet valve I44, the impeller m0- tor 49 and the signal light 220.

Themechanism for controlling the operation of the switches 268, 2 I4 and 2 I8 comprises a cam member 226 on and rotated by the shaft I64 driven by th timer motor I66. The switche 208, 2I4 and 2 ifimay be of similar construction and preferably each comprises a pair of spaced arms 228 and230 clamped in a support 232 of insulating material. Preferably the arms 228 and 230 are so arranged and clamped that both of them are stressed in the same direction and toward the outer surface 234 of the cam-226. The electrical circuit is closed through the engagement of the contacts 236 mountedon the opposed sides of the resilient arms 226 and 230.

The cam 226 on opposite sides is provided with pairs of annular track portions 236 and 240, which are spaced similarly to the spacing of the turned and offset ends 242 and 244 of the arms 222 and 230. The cam 226 is rotated in the direction indicated by the arrows in Figs. 6 and '7. It thus follows that the inclined portions 246 and 248 will cause the cam follower portions 242 and 244 to ride up the incline, and it will also be noted that the track 246 is abruptly terminated at 256 while the track 238 is abruptly terminated at 252 As heretofore stated the spring arms 220 and 230 are continuously urged toward the cam 226. When rotation of the cam 226 causes the end 224 to drop off the end'250 of the track 246, the contact 236 on the arm 228 is biased toward the cam 226 to separate the contacts 236, as shown in Fig. '7, to open the circuit. Thereafter rotation of the cam 226 to the point at which the end 242 drops off the end 252 of the track 236 will result in movement of the arm 230 toward the cam 226 to bring the contacts 266 together to close the circuit. Continued rotation of the cam 226 then brings the ends 242 and 244 up the inclined portion 246upon the crest of the tracks v238 and 240 with the circuit remaining closed.

It should beapparent to those skilled in the art that the contacts 226 will open and close with snap action and that with the arrangement described the circuit in which the contacts 236 are located can be opened and closed one or more times during the cycle of operation of the oar-r1226. It will be understood that the remaining circuits maybe controlled by the cam 226 in the manner described with reference to that specifically illustrated in Figs. 6 and 7.

To summarize the operation and cycles of operation controlled'by" the timer motor I60; the

dishwasher unit herein illustrated is designed to be connected in the usual manner to a cold water or hot water supply and to the sewer. In actual operation the dishwasher will be permanently plugged into a standard household electrical outlet, to assure at all times the availability of a tank of extremely hot water under the control of the thermostat I36. When it is desired to use the dishwasher, the cover 26 is raised and the dishes are loaded in suitable racks, not shown. The cover is then moved into its latched position, shown in dotted outline in Fig. 2, and the knob I80 is manually turned to the on position, which results in rotation of the shaft I10, advancing the cam 226 to close the switch H8 located in the timer circuit causing the timer motor I60 to operate. Thereafter the timer motor I60 takes over the rotation of the cam 226. Preferably the initial function of the timer motor I60 is to advance the cam 226 sufficiently to close the switch 208 in the impeller motor circuit to cause the impeller motor 40 to rotate the impeller 48, and at the same time through the action of the centrifugal unit associated with the impeller motor 40 to lower and close the drain valve I2. The operation of the motor 40 has the additional function of exerting an upward thrust on the rod I I8 to hold the latch I20 in a position resisting any attempt to open the lid 26 with the motor 40 running.

With the valve 12 closed, the timer motor I60 will advance the cam 226 sufliciently to close the switch 2 I4 in the inlet valve circuit to open the valve for a predetermined period to admit a measured quantity of water to the vat I2. At

the end of the initial washing cycle, which is determined by the design and rotation of the cam 226, the switch 208 is opened and the motor 40 stopped, permitting the spring I to lift the valve I2 from its seat to drain the washing water from the vat I2. Thereafter the switch 208 is closed and the motor 40 is started and the valve I2 is closed. Following this action the inlet valve switch 2I4, which was opened through rotation of the earn 226 after a predetermined amount of washing water has been admitted, is again closed to admit a, predetermined quantity of rinsing water into the vat I2. At the end of the rinsing cycle the pin I I6 is advanced by the cam I84 between the lever parts I00 and H2 with the result that when the cam 226 opens the impeller motor switch 208, stopping the motor 40, the action of the spring II! results in a downward pull upon the red I I8 against the action of the spring I28, which therefore swings to urge the latch I outwards into its releasing position, with respect to the plunger I26, thereby permitting the cover 26 to assume the steam venting position shown in full outline in Fig. 2.

After the rinse water has drained past the valve T2, the impeller motor circuit is again closed by closing the switch 208 through the action of the cam 226 and the impeller 48 is operated over a predetermined period to assist in drying the dishes. The timer I60 continues to rotate the cam 226, and after a predetermined period the impeller motor circuit is opened by opening the switch 208, stopping the motor 40. At the same time advancement of the cam I84 has carried the lobe I88 beyond engagement with the pin H6, which has been withdrawn by the spring I86, to the inoperative position shown in Fig. 2a. The timer motor I60 has now approached the end of its cycle of operation and shuts itself off through advancement of the cam 8 226. This completes the cycle of operation during which time the heater I34 in the water tank I32 has completely recovered and has available for the next cycle of operation of the dishwasher an adequate supply of extremely hot water. The cycle of operation can be repeated indefinitely.

Having thus described our invention, what we claim as new and desire to cover by Letters Patent is:

l. A dishwasher comprising a vat, a liquid impeller in said vat, a motor for driving said impeller, a valve for draining said vat, and a centrifugal actuator driven by said motor and operatively connected to said valve for closing said valve when the motor is started.

2. A dishwasher comprising a vat, a central drain structure in said vat, a vertical agitator shaft extending through said structure, a valve seat defined in said structure and surrounding said shaft, a valve, means supporting said valve for movement relative to said seat, a motor for driving said shaft, and an operative connection between said motor and said valve including rotational responsive means to open and close said valve upon stopping and starting of said motor.

3. A dishwasher comprising a vat, having a central opening in the bottom thereof, a drain structure closing said opening, a vertical agitator shaft concentrically supported in said drain structure, a valve seat in said structure and concentric with said shaft, a valve concentric with said shaft and supported for vertical movement relative to said seat to control the drainage of liquid from said vat, a motor for said shaft, rotational responsive means actuated by said motor, and an operative connection between said means and said valve for raising and lowering of said valve upon stopping and starting of said motor.

4. In an automatic dishwasher, a washing and rinsing chamber, an agitator for washing and rinse water located in said chamber, a motor for said agitator located outside of said chamber, a drain for said chamber, a valve for controlling said drain, mechanical means energized by said motor for operating said valve, a mechanical connection between said means and said valve to open said valve upon motor stoppage and to close said valve upon motor startage, and means for stopping and starting said motor to simultaneously control the agitation of water in said chamber and the drainage of water therefrom.

5. In an automatic dishwasher, a vat, a drain for said vat, a washing and rinsing water circulator in said vat, a supply of hot water connected with said vat, an operative connection between said drain and said circulator to open and close said drain including rotational responsive means, a timer, means under the control of said timer to start and stop said circulator to open and close said drain, a valve for regulating the flow of hot water from said supply to said vat, and means under the control of said timer to open said valve for a predetermined period after said circulator is started and said drain is closed.

6. An automatic dishwasher comprising a circulator, a motor for said circulator, a centrifugal actuator rotatable by said motor, a drain valve, and an operative connection between said actuator and said valve.

'7. In an automatic dishwasher, a vat, intermittently operable circulator means for directing cleansing liquid against articles placed in said vat, a supply of cleansing liquid connected to said vat, drain mechanism for said vat including means responsive to centrifugal forces for retention of cleansing liquid in said vat, a motor for actuating said means, an operative connection between said motor and said drain mechanism, means for controlling the intermittent operation of said motor and said first means, and means acting upon said drain mechanism for draining said vat substantially concurrently with the stoppage of said motor and said first means.

8. In an automatic dishwasher, a vat, circulator means located in said vat for intermittently directing cleansing liquid against articles placed in said vat, a drain opening defined in the base of said vat, means responsive to centrifugal forces preventing flow of liquid into said opening during periods of operation of said first means, a timer, means under the control of said timer for initiating and stopping the operation of said first means,

and means under the control of said timer for rendering said centrifugal responsive means in operative and to thereby effect draining to said vat through said drain opening, said last means acting upon said centrifugal responsive means substantially concurrently with the stoppage of said first means whereby drainage of cleansing liquid from said vat through said drain opening takes place during a period of arrested cleansing liquid in said vat.

9. In an automatic dishwasher, a vat having a 3 drain opening in the base thereof, drain mechanism for controlling the draining of cleansing liquid into said drain opening including means responsive to centrifugal forces for the reten- JOHN MACDONALD. GEORGE R. MEADOWCROFT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 821,250 Miller 1- May 22, 1906 1,123,876 Hiddleson Jan. 5, 1915 1,846,716 Geoliler et al Feb. 23, 1932 1,995,331 Snyder et al Mar. 26, 1935 2,025,571 Clark Dec. 24, 1935 2,142,929 Walker et a1 Jan. 3, 1939 2,281,852 Messier May 5, 1942 2,390,757 Voris Dec. 11, 1945 2,425,620 Kempton Aug. 12, 1947 2,517,109 Hollereth Aug. 1, 1950 2,595,660 Hollereth May 6, 1952 FOREIGN PATENTS Number Country Date 491,624 Germany Feb. 12, 1930 

